Underfeed mechanism for fuel beds



May 10, 1932. w. B. CHAP MAN UNDERFEED MECHANISM FOR FUEL BEDS 2 Shets-Sheet 1 Filed July 29, 1926 III "I ATTORNEYS- May 10, 1932. w. B. CHAPMAN UNDERFEED MECHANISM FOR FUEL BEDS Fild July 29, 1926 2 Sheets-Sheet 2 Patented May 10, 1932 UNITED STATES WILLIAM 3.,QHAI'MAN, OF JACKSON HEIGHTS, NEW YORK UNDERFEED MEGHA NIS MFOB FUEL BEDS Application filed July 29, 1926. Serial No. 125,620.

Heretofore in fuel beds fed from underneath difliculty has been encountered in obtaining a uniform fire bed, particularly a r !5 fire bed will be agitated uniformly through-- out and the ash removed equally from different zones of the fire bed, the above operations being carried on continuously and in conformity with the rate of fuel consumption, all to the-end that uniform conditions of combustion may be maintained in the firebed. Although ofgeneral application to fire beds, the invention is particularly useful in connection with gas producers, water gas generators and thelik-e wherein irregularities in the conditions of the, operation have resulted in wide variation in the quality and quantity of gas produced.

The invention also aims to provide a simple and efficient conveyor which will operate to feed the fuel upwardly into the fuel bed. Further objects and advantages of the invention will be in part obvious and in part specifically pointed out in the description hereinafter contained which taken in conjunction with the accompanying drawings, discloses a preferred embodiment thereof. Such embodiment, however, should be considered as merely illustrative of its principles. In the drawings Fig. 1 is a central vertical section through a gas producer having an underfeed mechanism constructed in accordance with the in- 'vention', the section being taken on line 1-1 of Fig. 2.

Fig. 2 is a transverse section on line 2 of Fig. 1. Fig. 3 is a transverse section on line 3-3 of Fig. 1.

Figs. 4 and 5 are diagrammatic views showing the fuel into the lower end of column ing the shape of certain blades used to assist in feeding the fuel.

Fig. 6 is a detailed section of the agitating member taken on line 6-6 of Fig. 2 looking in the direction of the arrows.

According to the present invention I provide underneath the fuel bed a hollow fuel feeding column through which the fuel is fed in an upward direction, and an agitating member sweeps through the lower zone of the fire bed in such manner as to agitate the latter from underneath and distribute the fresh fuel evenly throughout the fire bed. This agitating member also tends to eject the ash from the fire bed and thereby serves to maintain these essential conditions necessary for eflicient operation.

The invention is illustrated as applied to a gas producer having side walls 1 enclosing the fire bed 2 and a grate 3 which supports 70 the fire bed. The fuel is fed in through a hollow column 4 passing up centrally through grate 3 and shown as supported and rotated by a ratchet gear 5 which in turn is rotatably supported upon the hub 6 of a large gear which latter runs, on a ball-bearing raceway 8. The fuel is fed in from one or more spouts 9 which deliver it to a pan 10 carried by the large gear 7 and underlying the open bottom end of hollow column 4. The pan 10 also fixedly supoprts a screw 11 which is enclosed by hollow column 4 and rotates relative thereto, whereby fuel fed into the lower end of column 4 is raised through the column b this screw. The hollow column 4 is pre erably provided with a spiral ledge 4a to assist in elevating the fuel therethrough.

Suitable devices are provided for deliver- 4 in position to be operated on by the screw. As shown the pan 10 carries a set of blades 12 having instroking curved inner ends 13 thereon which tend to deliver the fuel into the openings 14 (Fig. 1) in the bottom of column 4,'and the lower end of the'column 4 carries oppositely curved blades 16 which cooperate with the blades above mentioned to accentuate the crowding action upon the fuel and thereby insure that the latter is gear 7.

fuel bed by the action of member 21;

properly engaged by the lower end of screw 11. As shown, the pan 10, its blades 12 and screw 11 are rotated faster than column 4 and an intermittent driving mechanism is provided for column 4, which derives its n10- tion from gear 7. In the present embodiment an engaging and releasing bar 17 is slidably carried by lugs 18 and 19 on gear 7, the inner end of the bar engaging the ratchet teeth on gear 5 and the outer end of the bar being provided with a lug 20 which engages fixed cam members 21 and 21* in such manner that cam member 21 throws the bar 17 into engagement with gear 5 and cam member 21 throws the bar 17 out of engagement with gear 5. Thus the cam member 21 ma be suitably spaced from cam member 21 (alternative positions of the cam member 21 being indicated in dotted lines in Fig. 3) around the periphery of ear 7 to cause the column 4 to be driven t rough the medium of bar 17 during the desired fraction of each revolution of After being fed up into the fire bed through column 4 as above described, the fuel tends to form a mound in the central zone of the fire bed leaving the peripheral zoneof the fire bed relatively shallow. Preferably the fuel discharge opening at the upper end of column 4, or the central opening in the agitating member hereinafter mentioned, is of restricted. area. as compared to the passageway in column 4 as a whole, in order to compress the fuel passing upwardly into thefirebed into a compact column sufliciently solid to pierce the comparatively deep rebed required for making gas of good quality, and reach the surfaces of the firebed instead of becoming dissipated in the lower portion of the firebed where it would become entrained with the partially or almost completely consumed outer mass of fuel which is traveling downwardly to pass out through the grate as ash. In order to distribute the fuel uniformly throughout'the fire bed, I provide an upstroking fuel distributing and fire bed agitating member 21 which is illustrated as extending substantially diametrically across the bottom of the fire bed and is fixed to the hollow column 4 so as to derive its rotary 1110- tion from the latter. The upstroking member 21' as it travels around producesa vertical undulating motion up through the fuel bed in addition to its outstroklng action, whereby the fuel which is projected upwardly in a central vertical path through the fire bed from hollow column 4 is thoroughly agitated while being spread outwardly over the illustrated form of the invention the arms of the agitator 21. are each provided with an inclined forward surface 22 (Fig. 6) which facilitates the upstroking action above referred to. Y I

The reference-tothe firebed itwill be 1m- In the sumed fuel which normally will underlie the former.

The agitating member 21' is also outstroking in its action, thereby tending to distribute the fuel evenly throughout the fire bed as above mentioned, and also crowding the ash 'out toward the walls of the producer. As

shown a water cooled annular metallic wear ring 23 rovided with inclined ribs 24 surrounds t 1e agitating member with the result that clinkers pushed outwardly by theagitator may be ground up between its ends and the ribs 24' on wear ring 23. The ribs 24 of the wear ring furthermore act to retard the horizontal movement of the lower portion of the firebed which is caused by the rotation of the agitating member and revent the firebed from turning bodily wit the agitating member.'

In the illustrated form of the invention the fire bed is supported by a stationary grate composed of sections 25 and 26 which are made relatively adjustable in some suitable manner, so as to permit the effective area of the grate openings as regards ash removal to be altered without substantially affecting the upward flow of the blast throu h the or acgrate. No particular construction complishing the above results is essential, but in the specific embodiment of the invention which is illustrated, the grate section 25 is fixedly supported from wear ring 23 and is provided with concentric series of arcuate grate openings 27 which flare outwardly at their bottoms as shown in Figure 1,and the grate sections 26 are in the form of rings of, triangular cross section which respectively underlie the concentric series of openings 27. The agitating member grinds up the ash sufficiently for it to pass through the openings 27 and thus by raising or lowering the rings 26 the rate of ash discharge may be adjusted. However, the above adjustments do not affect the grate openings to any substantial extent as far as their function is concerned of admitting the blast to the fire bed. As shown, the rings 26 rest upon eccentrics 28 carried by a suitable number of shafts 29 extending radially under the grate, whereby by turning the shafts 29, as by operating handles 30, the elevation of rings 26 may be adjusted.

The invention is illustrated as applied to either a producer of the dry bottom type or a water gas generator, a gas-tight housing 31 being provided to enclose the parts which are located underneath the grate and the blast being supplied through a suitable blast ported on the hollow column 4, and on which the ash is confined by an annular wall 34 until pushed off into an ash-discharge passageway 35, by a fixed sweep 36.

Since the space in the neighborhood of the axis of rotation of the agitating beam, through which water cooling connections most feasibly can be made, is preempted by the fuel feeding mechanism, I prefer to cool the agitator by causing wet ash to travel over its face. As shown, the upper grate section 25 is provided .vith a series of annular troughs 37, which are in communication with each other through the gaps 38 between grate openings 27 and have suitable water inlet and outlet connections 39 and 40 (Fig. 1 leading thereto, whereby the ash within the troughs is well saturated with water. The agitating member 21 furthermore is provided with tongues 41 which extend down into the troughs 37 and thus cause the wet ashto pass upwardly over the inclined forward surfaces 22 of the agitator arms and over the top of the latter.- As shown, the agitating member is also provided with openings 42 in the rear walls of its arms whereby the blast in passing through these openings also serves to cool the agitator.

In the operation of the producer therotary pan 10 will be turned at the speed necessary to feed in fuel at a rate corresponding to the desired rate of gas production, and the cam member 21 will be positioned to rotate agitating member 1 at the speed necessary to maintain the fire bed in proper condition. The .grate openings also will be adjusted to permit the removal of ash at a rate conforming substantially to the rate of ash production, thus enabling the producer to be continuously and mechanically operated, and

uniform gas making conditions in the fire bed maintained.

While the invention has been described as carried out by means of a specific apparatus, it will be obvious that many changes may be made therein without departing from itsprinciples, as defined in the appended claims.

I claim:

1. An underfeed mechanism for fire beds or the like comprising an upstanding hollow column, a feed screw enclosed thereby, a rotary pan enclosing the lower end of said column and means associated with said pan for delivering fuel into the lower end of said column.

2. An underfeed mechanism for fire beds or the like comprising an upstanding hollow column, a. feed screw enclosed thereby, and a rotary pan enclosing the lower end of said colunm, said pan carrying blades shaped to deliver fuel into the lower end of said column.

3. An underfeed mechanism for fire beds or the like comprising an upstanding hollow column, a feed screw enclosed'thereby, and

a rotary pan enclosing the lower end of said colUmn',-said column and pan carrying blades co acting" to deliver fuel into the lower end of said column.

4. An underfeed mechanism for fire beds a the lower end of said column for delivering fuel to be fed thereinto.

5. An underfeed mechanism for fire beds or the like comprising an upstanding hollow column, a feed screw .enclosed thereby, a ro- 4 tary pan surrounding the lower end of said column, said feed screw being fixed to said pan, and said column communicating with said pan.

6. An underfeed mechanism for fire beds or the. like comprising an upstandin hollow column, a feed screw enclosed there y, a rotary pan surrounding the lower end of said column, said feed screw being fixed to said pan, said column communicating with said pan, and means whereby said column and feed screw are driven in different periods of rotation. 7. An underfeed mechanism for fire beds or the like comprising an upstanding hollow column, a feed screw-enclosed thereby, a rotary pan surrounding the lower end of said column and connected to said feed screw to turn the latter, said column communicating withsaid pan, and a releasable clutch member for intermittently causing said hollow column to turn with said rotary pan.

8. In combination, a grate, an agitating member overlying said grate, a hollow column adapted to feed fuel upwardly through the-central portion of said grate and deliver the fuel to the fire bed above said agitating member, said column being connected to said agitating member, and means for rotating said column and agitating member.

9. In combination, a grate, an agitating member overlying said grate, a hollow column adapted to feed fuel upwardly through the central portion ofsaid'grate and deliver the fuel to the firebed above said agitating member, said column being connected to said agitating member, means for rotating said column and agitating member, a rotary ash receiving table beneath said grate and surrounding said column, and means for removing ash from said table.

10. An underfeed mechanism for fire beds or the like comprising an upstanding hollow column,-a feed screw enclosed thereby, a rotary p'an surrounding the lower end of said column and connected to said feed screw to turn the latter, said column communicating with said pan, a releasable clutch member for intermittently turning said hollow column with said rotary pan and a rotary agitating member operating in the lower portion of the grate, a rotary ash receiving receptacle under er portion of the the grate, a stationary sweep adapted to remove ash from said receptacle, and a rotary agitating member operating immediately above the grate about an axis substantially concentric with the axis of rotation of the ash-receiving receptacle.

' 12. The method of operating fire beds which comprises feeding fuel upwardly through and into the upper central portion of the fire bed from underneath at a rate conforming substantially to the desiredrate of fuel consumption, stroking the fuel outwardly to distribute it over the fire bed, grind ing up the ash, and withdrawing the ash from the lower portion of the fire. bed at a rate conforming substantially to the rate of ash production.

13. In combination, an underfeed mechanism for firebeds comprising means for feeding. fuel upwardly into the central zone of the fuel bed, a firebed supporting member, and up and outstroking agitating member disposed in the lower portion of the firebed immediately above said supporting member and adapted tocause a vertical undulating movement in the firebed, means for producing relative rotation between said member and the firebed, and means affording ash re moval from the firebed at its bottom portion.

14. In combination, means for feeding fuel upwardly into the central zone of a fuel bed,

a firebed supporting member, an up and outstroking agitatin beam disposed in the lowfirebed and adapted to cause a vertical undulating and outward movement in the firebed, said beam havin a fuel feeding opening therein through w ich the fuel is fed upwardly through and distributed out-- wardly' over the firebed, and means for producing relative rotation between the firebed and said beam.

15. In combination, a hollow fuel feeding column disposed substantially centrally with respect to a firebed, means whereby fuel may be fed upwardly through said column, a firebed supporting member, an up and outstroking agitating member disposed in the lower portion of the firebed immediatel above said supporting member and adapte to cause a vertical undulating movement in the firebed,

said a 'tating member having an openin throng which the fuel fed through sai column asses u wardly into the firebed, and means or pro ucing relative rotation be= tween the firebed and said agitating member. 16. In combination, a rotary hollowfuel feeding column disposed substantially centrally with respect to a firebed, means for feedmg fuel upwardly through said column,

a firebed supporting member, an up and outstroking agitatin member disposed in the lower portion 0 the firebed immediately above said supporting member and adapted to cause a vertlcal undulating movement in the firebed, said agitating member being so connected to the said column that the incoming fuel is delivered to the firebed above the agitating member, and means for rotating said agitatin member and column.

17. An un erfeed mechanism for firebeds, comprising an upstanding hollow column located substantially centrally with respect to the firebed, a. firebed supporting member, an up and outstroking agitating member disposed in the lower portion of the firebed and adapted to'cause a vertical undulatory movement in the firebed, a feed screw enclosed by said column, means for delivering fuel into the lower end of said column, means for producing relative horizontal travel between said agitating member and firebed, said agitating member being so related to said fuel feeding column that the incoming fuel is discharged into the firebed above the agitating member.

18. The method of operating firebeds which comprises feeding fuel upwardly through the central portion of the firebed to the top portion thereof, turning an agitating member through the lower part of the firebed to produce an outward and vertical undulating motion therein and distribute the fuel and promote uniform conditions of combustion respectively in annular zones of the firebed,

and withdrawing ash from the lower portion of the firebed to cause the partially consumed fuel to travel gradually downward around the central column 'of upwardly traveling fresh fuel.

19. An underfeed mechanism for firebeds or the like comprising an upstanding hollowcolumn, a feed screw enclosed thereby, means for producing relative rotation between said column and said feed screw and rotatable means operating concentrically about said column for delivering fuel into the lower end of said column.

20. An underfeed mechanism for firebeds or thelike, comprising a grate, an agitating member sweeping immediately over the grate and rotatable about the central portion thereof as an axis, an upstanding hollow column adapted to feed fuel upwardly through the central portion of the grate to a point above the agitating member, a feed screw enclosed by said column, and means fordelivering fuel into the lower end of said column.

21. In combination, a grate, an agitating .member overlying said grate and adapted to produce a vertical undulating movement in the firebed, means for feeding fuel upwardly through the central portion of the grate and delivering the fuelto the firebed above the agitatin member, an ash pit adapted to receive as passing through the grate and means for throttling the flow of ash through the grate.

22. In combination, a firebed supporting member, a firebed agitating member located immediately above said supporting member and rotatable relative thereto, said agitating member being out and upstroking in its action, means for feeding fuel upwardly into the central zone of the firebed, means afl'ording ash removal from the lower portion of the firebed and means for water coollng sa d agitating member.

23. In combination with a firebed support ing member, a fuel underfeed mechanism clinkers against the side walls to sizes small enough to pass out of the firebed, and means affording the discharge of ash from the firebed at the lower portion of the firebed.

In testimony'that I claim the foregoing, I have hereunto set myhand this 24th day of July, 1926. a

WILLIAM B; CHAPMAN. 

